package com.atguigu.guilimall.search.service.impl;

import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.TypeReference;
import com.atguigu.common.to.es.SkuEsModel;
import com.atguigu.common.utils.R;
import com.atguigu.guilimall.search.config.GulimallElasticSearchConfig;
import com.atguigu.guilimall.search.constant.EsConstant;
import com.atguigu.guilimall.search.feign.ProductFeignService;
import com.atguigu.guilimall.search.service.MallSearchService;
import com.atguigu.guilimall.search.vo.AttrResponseVo;
import com.atguigu.guilimall.search.vo.BrandVo;
import com.atguigu.guilimall.search.vo.SearchParam;
import com.atguigu.guilimall.search.vo.SearchResult;
import org.apache.lucene.search.join.ScoreMode;
import org.elasticsearch.action.search.SearchRequest;
import org.elasticsearch.action.search.SearchResponse;
import org.elasticsearch.client.RestHighLevelClient;
import org.elasticsearch.index.query.BoolQueryBuilder;
import org.elasticsearch.index.query.NestedQueryBuilder;
import org.elasticsearch.index.query.QueryBuilders;
import org.elasticsearch.index.query.RangeQueryBuilder;
import org.elasticsearch.search.SearchHit;
import org.elasticsearch.search.SearchHits;
import org.elasticsearch.search.aggregations.AggregationBuilders;
import org.elasticsearch.search.aggregations.bucket.nested.NestedAggregationBuilder;
import org.elasticsearch.search.aggregations.bucket.nested.ParsedNested;
import org.elasticsearch.search.aggregations.bucket.terms.ParsedLongTerms;
import org.elasticsearch.search.aggregations.bucket.terms.ParsedStringTerms;
import org.elasticsearch.search.aggregations.bucket.terms.Terms;
import org.elasticsearch.search.aggregations.bucket.terms.TermsAggregationBuilder;
import org.elasticsearch.search.builder.SearchSourceBuilder;
import org.elasticsearch.search.fetch.subphase.highlight.HighlightBuilder;
import org.elasticsearch.search.fetch.subphase.highlight.HighlightField;
import org.elasticsearch.search.sort.SortOrder;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.util.StringUtils;

import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;
import java.util.ArrayList;
import java.util.List;
import java.util.stream.Collectors;
/**
 * 检索服务
 */
@Service
public class MallSearchServiceImpl implements MallSearchService {
    @Autowired RestHighLevelClient restHighLevelClient;
    @Autowired ProductFeignService productFeignService;

    /**
     * 根据传进来的页面查询参数，去 es 中检索商品
     */
    @Override
    public SearchResult search(SearchParam param) {
        //动态构建出查询需要的DSL语句
        SearchResult result = null;
        //1、准备检索请求
        SearchRequest searchRequest = buildSearchRequest(param);    //调用《准备检索请求》方法
        try {
            //2、执行检索请求
            SearchResponse response = restHighLevelClient.search(searchRequest, GulimallElasticSearchConfig.COMMON_OPTIONS);
            //3、分析响应数据封装我们需要的格式
            result = buildSearchResult(response, param);    //调用《构建结果数据》方法
        } catch (IOException e) {
            e.printStackTrace();
        }
        return result;
    }


    /**
     * 准备检索请求
     * 模糊匹配、过滤（按照属性、分类、品牌、价格区间、库存），排序，分页，高亮，聚合分析
     */
    private SearchRequest buildSearchRequest(SearchParam param) {
        //1、用于构建 DSL 语句
        SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
        /**
         * 过滤（按照属性、分类、品牌、价格区间、库存）
         */
        //2、构建 bool-query
        BoolQueryBuilder boolQuery = QueryBuilders.boolQuery();
        sourceBuilder.query(boolQuery);
        //2.1 must-模糊匹配
        if (!StringUtils.isEmpty(param.getKeyword())) {
            boolQuery.must(QueryBuilders.matchQuery("skuTitle", param.getKeyword()));
        }
        //2.2.1 filter-按照三级分类id查询
        if (param.getCatalog3Id() != null) {
            boolQuery.filter(QueryBuilders.termQuery("catalogId", param.getCatalog3Id()));
        }
        //2.2.2 filter-按照品牌id查询
        if (param.getBrandId() != null && param.getBrandId().size() > 0) {
            boolQuery.filter(QueryBuilders.termsQuery("brandId", param.getBrandId()));
        }
        //2.2.3 filter-按照是否有库存进行查询
        if (param.getHasStock() != null) {
            boolQuery.filter(QueryBuilders.termQuery("hasStock", param.getHasStock() == 1));    //1有库存
        }
        //2.2.4 filter-按照价格区间进行查询 (价格区别类似于：1_500/_500/500_)
        RangeQueryBuilder rangeQueryBuilder = QueryBuilders.rangeQuery("skuPrice");
        if (!StringUtils.isEmpty(param.getSkuPrice())) {
            String[] prices = param.getSkuPrice().split("_");    //将 价格 按照 "_" 进行分割 (比如分割成：1 _ 500  _500  500_)
            if (prices.length == 1) {    //如果长度为 1，说明是大于或小于单个值
                if (param.getSkuPrice().startsWith("_")) {    //如果当前价格是以 "_" 开头的 (比如 _500，说明是小于500)
                    rangeQueryBuilder.lte(Integer.parseInt(prices[0]));    //那构造条件就是 小于第一个值 (比如小于500)
                } else {
                    rangeQueryBuilder.gte(Integer.parseInt(prices[0]));    //否则构造条件就是 大于第一个值 (比如：500_，大于500)
                }
            } else if (prices.length == 2) {    //如果长度为 2，说明是一个价格区间 (比如：1_500，表示大于1小于500)
                //_6000会截取成["","6000"]
                if (!prices[0].isEmpty()) {
                    rangeQueryBuilder.gte(Integer.parseInt(prices[0]));
                }
                rangeQueryBuilder.lte(Integer.parseInt(prices[1]));
            }
            boolQuery.filter(rangeQueryBuilder);
        }
        //2.2.5 filter-按照属性进行查询
        List<String> attrs = param.getAttrs();
        if (attrs != null && attrs.size() > 0) {
            //attrs 类似于: attrs=1_5寸:8寸&2_16G:8G
            attrs.forEach(attr -> {    //attr 类似于: attr=1_5寸:8寸 或者 attr=2_16G:8G
                //细节：这个放里面，让每个都都生成一个 nested，避免一个商品的属性，比如商品id，既是15又是16
                BoolQueryBuilder queryBuilder = new BoolQueryBuilder();
                String[] attrSplit = attr.split("_");    //以 "_" 进行分割 (比如：2  16G:8G)
                queryBuilder.must(QueryBuilders.termQuery("attrs.attrId", attrSplit[0]));    //检索的属性的id
                String[] attrValues = attrSplit[1].split(":");    //以 ":" 进行分割 (比如：16G  8G)
                queryBuilder.must(QueryBuilders.termsQuery("attrs.attrValue", attrValues));    //检索的属性的值
                //每一个必须都得生成一个 nested 查询
                NestedQueryBuilder nestedQueryBuilder = QueryBuilders.nestedQuery("attrs", queryBuilder, ScoreMode.None);
                boolQuery.filter(nestedQueryBuilder);
            });
        }
        //3、把上面的所有条件都拿来进行封装
        sourceBuilder.query(boolQuery);

        //4、排序，分页，高亮，
        //4.1 排序  eg:sort=saleCount_desc/asc    saleCount: 排序字段    desc/asc: 降序/升序
        if (!StringUtils.isEmpty(param.getSort())) {
            String[] sortSplit = param.getSort().split("_");    //以 "_" 进行分割 (比如：saleCount  desc/asc)
            sourceBuilder.sort(sortSplit[0], sortSplit[1].equalsIgnoreCase("asc") ? SortOrder.ASC : SortOrder.DESC);
        }

        //4.2 分页
        sourceBuilder.from((param.getPageNum() - 1) * EsConstant.PRODUCT_PAGESIZE);    //PRODUCT_PAGESIZE = 2
        sourceBuilder.size(EsConstant.PRODUCT_PAGESIZE);    //PRODUCT_PAGESIZE = 2

        //4.3 高亮, Keyword类型才高亮显示
        if (!StringUtils.isEmpty(param.getKeyword())) {
            HighlightBuilder highlightBuilder = new HighlightBuilder();
            highlightBuilder.field("skuTitle");    //要高亮的字段
            highlightBuilder.preTags("<b style='color:red'>");    //前置标签
            highlightBuilder.postTags("</b>");    //后置标签
            sourceBuilder.highlighter(highlightBuilder);
        }

        //5、聚合分析
        //5.1 按照品牌聚合
        TermsAggregationBuilder brand_agg = AggregationBuilders.terms("brand_agg").field("brandId").size(50);
        //品牌聚合的子聚合，subAggregation：子聚合
        TermsAggregationBuilder brand_name_agg = AggregationBuilders.terms("brand_name_agg").field("brandName").size(1);
        TermsAggregationBuilder brand_img_agg = AggregationBuilders.terms("brand_img_agg").field("brandImg");
        brand_agg.subAggregation(brand_name_agg);
        brand_agg.subAggregation(brand_img_agg);
        sourceBuilder.aggregation(brand_agg);

        //5.2 按照分类聚合
        TermsAggregationBuilder catalog_agg = AggregationBuilders.terms("catalog_agg").field("catalogId").size(20);
        TermsAggregationBuilder catalog_name_agg = AggregationBuilders.terms("catalog_name_agg").field("catalogName").size(1);
        //分类聚合的子聚合，subAggregation：子聚合
        catalog_agg.subAggregation(catalog_name_agg);
        sourceBuilder.aggregation(catalog_agg);

        //5.3 按照属性聚合
        NestedAggregationBuilder nestedAggregationBuilder = new NestedAggregationBuilder("attr_agg", "attrs");
        //按照 attrId 聚合
        TermsAggregationBuilder attr_id_agg = AggregationBuilders.terms("attr_id_agg").field("attrs.attrId");
        //按照 attrId 聚合之后再按照 attrName 和 attrValue 聚合
        TermsAggregationBuilder attr_name_agg = AggregationBuilders.terms("attr_name_agg").field("attrs.attrName").size(1);
        TermsAggregationBuilder attr_value_agg = AggregationBuilders.terms("attr_value_agg").field("attrs.attrValue").size(50);
        attr_id_agg.subAggregation(attr_name_agg);    //subAggregation：子聚合
        attr_id_agg.subAggregation(attr_value_agg);

        nestedAggregationBuilder.subAggregation(attr_id_agg);
        sourceBuilder.aggregation(nestedAggregationBuilder);

        String s = sourceBuilder.toString();
        System.out.println("构建的DSL" + s);

        //6、封装检索请求并返回                         PRODUCT_INDEX = "gulimall_product"    sourceBuilder 为当前方法封装的所有检索条件
        SearchRequest request = new SearchRequest(new String[]{EsConstant.PRODUCT_INDEX}, sourceBuilder);
        return request;
    }


    /**
     * 构建结果数据
     * SearchResponse response 的参数，可通过 debug 的方式拿到
     */
    private SearchResult buildSearchResult(SearchResponse response, SearchParam param) {
        SearchResult result = new SearchResult();
        //1、返回的所有查询到的商品
        SearchHits hits = response.getHits();
        List<SkuEsModel> esModels = new ArrayList<>();

        if (hits.getHits() != null && hits.getHits().length > 0) {
            for (SearchHit hit : hits.getHits()) {
                String sourceAsString = hit.getSourceAsString();
                SkuEsModel esModel = JSON.parseObject(sourceAsString, SkuEsModel.class);
                //设置高亮内容
                if (!StringUtils.isEmpty(param.getKeyword())) {
                    HighlightField skuTitle = hit.getHighlightFields().get("skuTitle");
                    esModel.setSkuTitle(skuTitle.fragments()[0].string());
                }
                esModels.add(esModel);
            }}
        result.setProducts(esModels);

        //2、当前所有商品涉及到的所有属性信息   ===========以下从聚合信息获取到=============
        List<SearchResult.AttrVo> attrVos = new ArrayList<>();
        ParsedNested attr_agg = response.getAggregations().get("attr_agg");
        ParsedLongTerms attr_id_agg = attr_agg.getAggregations().get("attr_id_agg");

        for (Terms.Bucket bucket : attr_id_agg.getBuckets()) {
            SearchResult.AttrVo attrVo = new SearchResult.AttrVo();
            //得到属性的id
            long attrId = bucket.getKeyAsNumber().longValue();
            //得到属性的名字
            String attrName = ((ParsedStringTerms) bucket.getAggregations().get("attr_name_agg")).getBuckets().get(0).getKeyAsString();
            //得到属性的所有值
            List<String> attrValues =
                    ((ParsedStringTerms) bucket.getAggregations().get("attr_value_agg")).getBuckets().stream().map(item -> {
                String keyAsString = item.getKeyAsString();
                return keyAsString;
            }).collect(Collectors.toList());
            attrVo.setAttrId(attrId);
            attrVo.setAttrName(attrName);
            attrVo.setAttrValue(attrValues);
            attrVos.add(attrVo);
        }
        result.setAttrs(attrVos);

        //3、当前所有商品涉及到的所有品牌信息
        List<SearchResult.BrandVo> brandVos = new ArrayList<>();
        ParsedLongTerms brand_agg = response.getAggregations().get("brand_agg");
        for (Terms.Bucket bucket : brand_agg.getBuckets()) {
            SearchResult.BrandVo brandVo = new SearchResult.BrandVo();
            //得到品牌的id
            long brandId = bucket.getKeyAsNumber().longValue();
            //得到品牌的名
            String brandName = ((ParsedStringTerms) bucket.getAggregations().get("brand_name_agg")).getBuckets().get(0).getKeyAsString();
            //得到品牌的图片
            String brandImg = ((ParsedStringTerms) bucket.getAggregations().get("brand_img_agg")).getBuckets().get(0).getKeyAsString();
            brandVo.setBrandId(brandId);
            brandVo.setBrandName(brandName);
            brandVo.setBrandImg(brandImg);
            brandVos.add(brandVo);
        }
        result.setBrands(brandVos);

        //4、当前商品所涉及的分类信息
        ParsedLongTerms catalog_agg = response.getAggregations().get("catalog_agg");

        List<SearchResult.CatalogVo> catalogVos = new ArrayList<>();
        List<? extends Terms.Bucket> buckets = catalog_agg.getBuckets();
        for (Terms.Bucket bucket : buckets) {
            SearchResult.CatalogVo catalogVo = new SearchResult.CatalogVo();
            //得到分类id
            String keyAsString = bucket.getKeyAsString();
            catalogVo.setCatalogId(Long.parseLong(keyAsString));

            //得到分类名
            ParsedStringTerms catalog_name_agg = bucket.getAggregations().get("catalog_name_agg");
            String catalog_name = catalog_name_agg.getBuckets().get(0).getKeyAsString();
            catalogVo.setCatalogName(catalog_name);
            catalogVos.add(catalogVo);
        }
        result.setCatalogs(catalogVos);

        //===========以上从聚合信息获取到=============

        //5、分页信息-页码
        result.setPageNum(param.getPageNum());
        //6、分页信息-总记录数
        long total = hits.getTotalHits().value;
        result.setTotal(total);
        //7、分页信息-总页码-计算    11 / 2 = 5 余 1
        int totalPages = total % EsConstant.PRODUCT_PAGESIZE == 0 ?
                (int) total / EsConstant.PRODUCT_PAGESIZE : ((int) total / EsConstant.PRODUCT_PAGESIZE + 1);
        result.setTotalPages(totalPages);

        List<Integer> pageNavs = new ArrayList<>();
        for (int i = 1; i < totalPages; i++){
            pageNavs.add(i);
        }
        result.setPageNavs(pageNavs);

        //8、构建面包屑导航
        if (param.getAttrs() != null && param.getAttrs().size() > 0) {
            List<SearchResult.NavVo> collect = param.getAttrs().stream().map(attr -> {
                //8.1 分析每一个 attrs 传过来的参数值，比如 attr=15_海思
                SearchResult.NavVo navVo = new SearchResult.NavVo();
                String[] s = attr.split("_");    //按 "_" 进行分割，比如将 15_海思 分割成 15 和 海思
                navVo.setNavValue(s[1]);    //那第二个值，也就是 海思
                R r = productFeignService.attrInfo(Long.parseLong(s[0]));    //调用《根据 属性id 查询属性信息》方法
                result.getAttrIds().add(Long.parseLong(s[0]));
                if (r.getCode() == 0) {
                    AttrResponseVo data = r.getData("attr", new TypeReference<AttrResponseVo>() {});
                    navVo.setNavName(data.getAttrName());
                } else {
                    navVo.setNavName(s[0]);
                }

                //8.2 取消了这个面包屑以后，我们要跳转到哪个地方，将请求地址 url 里面的当前条件置空
                //拿到所有的查询条件，去掉当前的
                String replace = replaceQueryString(param, attr, "attrs");    //调用《替换请求地址 以及 解决编码 和 空格的问题》方法
                navVo.setLink("http://search.gulimall.com/list.html?" + replace);    //设置要跳转到的位置

                return navVo;
            }).collect(Collectors.toList());

            result.setNavs(collect);
        }

        //品牌相关的面包屑导航
        if (param.getBrandId() != null && param.getBrandId().size() > 0){
            List<SearchResult.NavVo> navs = result.getNavs();
            SearchResult.NavVo navVo = new SearchResult.NavVo();
            navVo.setNavName("品牌");
            //远程查询所有品牌
            R r = productFeignService.brandsInfo(param.getBrandId());    //调用《根据 品牌id 查询品牌信息》方法
            if (r.getCode() == 0){
                List<BrandVo> brand = r.getData("brand", new TypeReference<List<BrandVo>>() {});
                StringBuffer buffer = new StringBuffer();
                String replace = "";
                for (BrandVo brandVo : brand) {
                    buffer.append(brandVo.getBrandName() + ";");
                    //调用《替换请求地址 以及 解决编码 和 空格的问题》方法
                    replace = replaceQueryString(param, brandVo.getBrandId() + "", "brandId");
                }
                navVo.setNavValue(buffer.toString());
                navVo.setLink("http://search.gulimail.com/list.html?" + replace);
            }
            navs.add(navVo);
            result.setNavs(navs);
        }
        return result;
    }

    /**
     * 替换请求地址 以及 解决编码 和 空格的问题
     */
    private String replaceQueryString(SearchParam param, String value, String key) {
        String encode = null;
        try {
            encode = URLEncoder.encode(value, "UTF-8");    //解决下面替换时 replace 出现乱码的问题
            encode.replace("+", "%20");    //浏览器对空格的编码和Java不一样，差异化处理
        } catch (Exception e) {
            e.printStackTrace();
        }
        //比如将 attrs=15_海思 替换为" "(置空)
        String replace = param.get_queryString().replace("&" + key + "=" + encode, "");
        return replace;
    }
}
